Light emitting materials of higher molecular weight (light emitting polymer) are soluble in a solvent and capable of forming a light emitting layer in a light emitting device by an application method unlike those of lower molecular weight, and thus, light emitting polymers are variously investigated and those containing an aromatic ring in the main chain are known.
As monomers for producing these light emitting polymers, aromatic compounds having two condensation-reactive functional groups (for example, WO97/05184, and the like) are used.
On the other hand, there has been recently conducted a trial of making a branched polymer compound for improving the performance of a light emitting polymer and the like, and aromatic compounds having three condensation-reactive functional groups which can be used as monomers of the compound are disclosed (for example, WO96/17035). However, for producing various branched polymer compounds, their kinds are not sufficient.